<template>
      <div class="list" ref="wrapper"><!--ref获取dom元素-->
            <div>
            <div class="area">
                  <div class="title border-topbottom">当前城市</div>
                        <div class="button-list">
                              <div class="button-wrapper">
                                    <div class="button">{{this.currentCity}}</div>
                              </div>
                        </div>
                  </div>
                  <div class="area">
                        <div class="title border-topbottom">热门城市</div>
                        <div class="button-list">
                              <div class="button-wrapper" v-for="item of hot"
                               :key="item.id"
                               @click="handleCityClick(item.name)"
                              >
                                    <div class="button">{{item.name}}</div>
                              </div>
                        </div>
                  </div>
                  <div
                          class="area"
                          v-for="(item,key) of cities"
                          :key="key"
                          :ref="key"
                  >
                        <div class="title border-topbottom">{{key}}</div>
                        <div class="item-list">
                              <div
                                class="item border-bottom"
                                v-for="innerItem of item"
                                :key="innerItem.id"
                                @click="handleCityClick(innerItem.name)"
                              >
                                    {{innerItem.name}}
                              </div>
                        </div>
                  </div>
            </div>
      </div>
</template>

<script>
 import Bscroll from 'better-scroll'
 import {mapState, mapMutations} from 'vuex'
  export default {
    name: "CityList",
   props:{
     hot:Array,
    cities:Object,
    letter: String
   },
    computed:{
          ...mapState({
                currentCity:'city'/*将数据映射到计算属性中*/
          })
    },
   methods:{
         handleCityClick (city) {
               //this.$store.commit('changeCity',city);/*调用action方法时一定要调用dispatch方法*/
               this.changeCity(city);
               this.$router.push('/')/*js编程式的路由跳转*/
         },
         ...mapMutations(['changeCity'])/*映射mutation*/
   },
   mounted() {
     this.scroll=new Bscroll( this.$refs.wrapper)
   },
   watch:{/* 监听器，监听letter的变化，一旦letter改变就执行下面发方法*/
     letter () {
            if (this.letter) {
                  const element=this.$refs[this.letter][0];
                  this.scroll.scrollToElement(element)/*自动滚动到某一元素上*/
            }
     }
   }
  }
</script>

<style lang="stylus" scoped>
      @import "../../assets/styles/varibles.styl"
      .border-topbottom
        &:before
          border-color #ccc
        &:after
          border-color #ccc
      .border-bottom
            &:before
              border-color #ccc
      .list
       overflow hidden
       position absolute
       top 1.58rem
       left 0
       right 0
       bottom 0
       .title
        line-height .54rem
        background #eee
        padding-left .2rem
        color #666
        font-size .26rem
       .button-list
        overflow hidden
        padding .1rem .6rem .1rem .1rem
        .button-wrapper
         float left
         width 33.33%
         .button
          margin .1rem
          padding .1rem 0
          text-align center
          border .02rem solid #ccc
          border-radius .06rem
       .item-list
         .item
          line-height .76rem
          padding-left .2rem

</style>